One vertex per element, one color per generator, with an edge from x to x·s.
(2,4)(5,6)(7,10)(8,9)(11,12)(13,14,20,18,19,24,17,23)(15,25,26,22,27,21,16,28)(6,9)(7,11)(13,15)(14,21)(16,17)(18,28)(19,27)(20,26)(22,23)(24,25) involution — undirected(1,2,3,4)(13,16,19,26)(14,22,24,28)(15,17,27,20)(18,21,23,25)(5,7,8,11)(6,10,9,12)(13,17,19,20)(14,23,24,18)(15,26,27,16)(21,28,25,22)(6,9)(10,12)(13,18,20,24,19,23,17,14)(15,22,26,21,27,28,16,25)A Cayley diagram is a choice, not a fact about the group. Another drawing of this group — in a book, or on a different generating set — may look nothing like this one.